Steven Tyler has given the most in-depth account of his weeklong stint jamming with Led Zeppelin. Following the success of the band's 2007 London reunion show -- now available as Celebration Day -- Jimmy Page, John Paul Jones, and Jason Bonham kept rehearsing in hopes that Robert Plant would soon join them, but when Plant showed no interest, the trio sought out outside singers for a possible new project.

Tyler told his side of the story to Classic Rock magazine, recalling: "I went over and played with Jimmy and the rest of them in (summer 2008). It wasn't an audition to be in Zeppelin, it was an audition to play with Zeppelin. We were going to do a couple of stadiums. And then while I was there, Jimmy spoke to me about maybe doing an album. I went home and thought about it for a couple of days, and I got back to him and said, 'Look Jimmy, you're in an iconic band and so am I. I can't in good faith, leave my band and be in your band.'"

He went on to say, "We played all day for a week. Every time we took a break I smoked a cigar and Jimmy smoked a cigarette. We went out back and spoke with Jimmy about everything on the planet. It started out with, 'Jimmy, you have no idea how grateful I am to have the chance to come over and jam with you guys.' And he goes, 'Well, maybe we can play some shows together.' And I said, 'Stop right there. I'm playing in a band with John Paul Jones?'"

Tyler explained that although he had a blast, he soon realized that he had his own band situation to work out: "They let me sing every song I wanted; 'Black Dog,' 'Stairway To Heaven.' But it was just a week. And yeah, Jimmy asked me to do some stuff with him. But I didn't want to be Coverdale/Page. Plus, I figured in the time it would take to do that, I could rally my own band back together. So, was I gonna be in Jimmy's band? No. But what an honor."

Steven Tyler told us that regardless of Aerosmith's well-documented ups and downs -- unlike many of their peers -- the band has proven to be truly unstoppable: "We have that one thing about us, that we never quit, we never gave up, we always went on tour, and we always did an album. If you were to ask me, 'What's the greatest thing Aerosmith ever did?' -- we stuck around."